asp.net 组合模式的一个例子_PHP教程

php中文网

发布时间：2016-07-21 15:15:11

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来源于php中文网

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复制代码代码如下:

 
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
namespace Test 
{ 
class Program 
{ 
static void Main(string[] args) 
{ 
var customer = new Customer 
{ 
IsActive = true, 
LateFees = 100M, 
TotalRentNumber = 10 
}; 
Console.WriteLine(customer.CanRent()); 
Console.ReadKey(); 
} 
} 
public interface ISpecification
{ 
/// 
/// 是否可以租赁 
/// 
bool IsSatisfiedBy(T entity); 
/// 
/// 与操作 
/// 
ISpecification And(ISpecification other); 
/// 
/// 否操作 
/// 
ISpecification Not(); 
} 
/// 
/// 基类 
/// 
public abstract class CompositeSpecification : ISpecification
{ 
public abstract bool IsSatisfiedBy(T candidate); 
public ISpecification And(ISpecification other) 
{ 
return new AndSpecification(this, other); 
} 
public ISpecification Not() 
{ 
return new NotSpecification(this); 
} 
} 
/// 
/// 与操作 
/// 
public class AndSpecification : CompositeSpecification
{ 
private ISpecification leftSpecification; 
private ISpecification rightSpecification; 
public AndSpecification(ISpecification leftSpecification, ISpecification rightSpecification) 
{ 
this.leftSpecification = leftSpecification; 
this.rightSpecification = rightSpecification; 
} 
public override bool IsSatisfiedBy(T entity) 
{ 
return leftSpecification.IsSatisfiedBy(entity) && rightSpecification.IsSatisfiedBy(entity); 
} 
} 
///
///否操作 
/// 
public class NotSpecification : CompositeSpecification
{ 
private ISpecification innerSpecification; 
public NotSpecification(ISpecification innerSpecification) 
{ 
this.innerSpecification = innerSpecification; 
} 
public override bool IsSatisfiedBy(T entity) 
{ 
return !innerSpecification.IsSatisfiedBy(entity); 
} 
} 
/// 
/// 是否达到最大的规定租赁数 
/// 
public class HasReachedMaxSpecification : CompositeSpecification
{ 
public override bool IsSatisfiedBy(Customer entity) 
{ 
return entity.TotalRentNumber > 5; 
} 
} 
/// 
/// 是否激活 
/// 
public class CustomerActiveSpecification : CompositeSpecification
{ 
public override bool IsSatisfiedBy(Customer entity) 
{ 
return entity.IsActive; 
} 
} 
/// 
/// 是否欠费 
/// 
public class CustomerHasLateFeesSpecification : CompositeSpecification
{ 
public override bool IsSatisfiedBy(Customer entity) 
{ 
return entity.LateFees > 0; 
} 
} 
public class Customer 
{ 
private ISpecification hasReachedRentalThreshold; 
private ISpecification customerIsActive; 
private ISpecification customerHasLateFees; 
public Customer() 
{ 
hasReachedRentalThreshold = new HasReachedMaxSpecification(); 
customerIsActive = new CustomerActiveSpecification(); 
customerHasLateFees = new CustomerHasLateFeesSpecification(); 
} 
/// 
/// 用户租赁DVD数量 
/// 
public int TotalRentNumber 
{ 
get; 
set; 
} 
/// 
/// 账户是否激活 
/// 
public bool IsActive 
{ 
get; 
set; 
} 
/// 
/// 用户之前是否还欠费 
/// 
public decimal LateFees 
{ 
get; 
set; 
} 
public bool CanRent() 
{ 
ISpecification canRent = customerIsActive.And(hasReachedRentalThreshold.Not()).And(customerHasLateFees.Not()); 
return canRent.IsSatisfiedBy(this); 
} 
} 
} 